Synthesis of 2-aminoazulene derivatives. Nucleophilic and palladium-catalyzed amination of 2-substituted azulene

Amination of 2-substituted azulene was carefully examined using several types of amines, and the scope and limitation of substrates and reagents in these direct nucleophilic aminations were found. The synthesis of 2-aminoazulenes was successfully achieved by the reaction of 2-bromoazulene with several amines via palladium-catalyzed amination.     

Electron-impact induced fragmentation of 2-substituted pyridines and picolines

The fragmentation patterns obtained upon electron impact on 2-nitro-, 2-chloro, and 2-aminopyridines, as well as those of the corresponding 3-, 4-, 5- and 6-picolines were examined. There was considerable departure from those patterns reported for the corresponding benzenoid derivatives. Although the molecular ion from 2-nitro-3-picoline did not show fragment ions attributable to an “ortho-effect” (unlike o-nitrotoluene), those from 2-chloro- and 2-amino-3-picolines did show a loss of HCl and NH₃, respectively. Quite unexpectedly the ions from 2-chloro- and 2-amino-6-picolines also lost HCl and NH₃. Such meta-eliminations for the 2-substituted-6-picolines are postulated to be preceeded by either hydrogen or methyl migration. The mass spectra of 2-pyridone, 2-pyridthione and their respective 3-, 4-, 5- and 6-methyl analogs were also studied. The primary fragmentations of the 2-pyridones were as expected from those reported in the literature. The ions from 3- and 6-methyl-2-pyridones lost water also, the former being another example of an “ortho-effect” observed in this series. Of the thiones, the fragmentations of 3-methyl-2-pyridthione proved most unique since its molecular ion showed besides the loss of HS, the pronounced elimination of H₂S, the latter presumably due to an “ortho-effect.” Figures are presented to illustrate the patterns and metastable ions are indicated when found for the transitions discussed.     

Reaction of esters of 2-substituted 5-pyrimidinecarboxylic acids with hydrazine hydrate

The reaction of methyl esters of 2-substituted 5-pyrimidinecarboxylic acids with hydrazine hydrate at 0–5°C results in the nucleophilic substitution of readily eliminating groups (Cl, CH₃O, CH₃S) at the position 2 of the pyrimidine ring, and, on the boiling with the 80% aqueous solution of hydrazine hydrate, the reaction is accompanied by the formation of hydrazides. The dimethylamino group at thepposition 2 of the pyrimidine ring is not substituted by hydrazine.Vilnius University, Vilnius 2006, Lithuania Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1528–1530, November, 1999.     

Reaction of 9-substituted 1-aminoadenine with hydrazine

Reaction of 9-substituted (methyl or benzyl) 1-aminoadenines 1 with hydrazine afforded 9-substituted 6-hydrazinopurines 2 and 1-substituted 5-ammo-4-(4-amino-1,2,4-triazol-3-yl)imidazole ( 4 ). The product ratio of 2 to 4 rose with increasing amounts of methanol used as the solvent. When the same reaction was carried out using 1,9-dimethyladenine instead of 1 , compounds 2 and 4 were also obtained with N⁶,9-dimethyladenine. A possible mechanism for formation of 2 and 4 is discussed.     

Catalytic C-H amination with aromatic amines

Aniline joins the club: A β-diketiminato copper(I) catalyst enables C-H amination of anilines employing low catalyst loadings to preclude oxidation to the diazene ArN=NAr. Electron-poor anilines are particularly resistant towards diazene formation and participate in the amination of strong and unactivated C-H bonds. N-alkyl anilines also take part in C-H amination.     

Selective amination of 1-substituted uracils

Conclusions 1-Substituted uracils were subjected to selective amination at the fourth carbonyl group by reaction with phosphorous acid tris-dimethylamide and phosphoric acid tris-anilide.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1198–1200, May, 1970.     

2-取代吡啶衍生物的CNDO/2计算和分子光谱研究

本文用CNDO/2方法计算了吡啶及其2-取代衍生物,测了其紫外光谱.通过红外,紫外光谱和量子化学计算的综合分析,确定2-吡啶酮与2-羟基吡啶是互变异构体,并推断2-氨基吡啶的互变异构体存在,从而很好地得到了此系列紫外光谱的线性规律.     

Hexafluorosilicates of 2-substituted anilinium derivatives

The reaction of 45% fluorosilicic acid with methanol solutions of several 2-substituted anilines(L) gave hexafluorosilicates (LH)₂SiF₆. The products were studied by elemental analysis, IR spectroscopy, mass spectrometry, and thermogravimetry. The solubility and the hydrolytic stability of the salts were estimated. The structure of the complex [CH₃O(O)CC₆H₄NH₃]₂SiF₆ was determined by single-crystal X-ray diffraction. The ionic structure is composed of centrosymmetric SiF ₆ ^2? anions (the average Si-F bond length is 1.679(1) Å) and the [CH₃O(O)CC₆H₄NH₃]⁺ cations. The NH ₃ ⁺ group is the donor for the inner-cation H-bond with the carbonyl oxygen atom (NH···O), and for two ion-ion H-bonds (NH···F). The Si-F bond lengths correlate with the strengths of the H-bonds involving the corresponding fluorine atoms.     

Synthesis of 2-substituted bamipine derivatives

2-Substituted derivatives of bamipine and its 1-phenyl analogue have been prepared in several steps from dihydropyridine-2(1H)-thiones. The configurations and the conformations of the formed diastereoisomers have been investigated by NMR spectroscopy. The antimycobacterial activities of the title compounds have been examined.     

Synthesis of 2-substituted 3-oxoisothiazolo[5,4-b]pyridines

Starting with 2-chloro-3-pyridinecarboxylic acid 1 , three different routes to prepare 3-oxoisothiazolo-[4,5-b]pyridines 10 were studied.     

Study of plant coumarins: XIV. Catalytic amination of 7-hydroxycoumarin derivatives

Catalytic amination of 7-hydroxy-6-cyanocoumarin or 7-hydroxy-6-methoxycarbonylcoumarin triflates with substituted anilines, isoquinolin-5-amine, 1H-pyrazol-3-amine, or amino acids of penicillin series affords the corresponding 7-(N-substituted) aminocoumarins. In the amination of the mentioned triflates and also of peuruthenicine tosilate with 2-(piperidin-1-yl)aniline the catalytic system Pd(OAc)₂-BINAP has been efficient.     

Synthesis of 5-substituted cyanofurans and their reaction with hydrazine

Based on the Schmidt reaction, a new method has been developed for the preparation of nitriles in furan series from the corresponding furfural derivatives. Depending on conditions, the reaction of 5-substituted cyanofurans with hydrazine leads to amidrazones, N-aminotriazoles, or 1,2,4,5-dihydrotetrazines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 181–186, February, 1986.     

Reaction of dialuric acid with hydrazine derivatives

In the condensation of dialuric, thiodialuric, and acetyldialuric acids with hydrazine derivatives, the ketone character of the CO group in the 2 position is manifested only in the case of acetyldialuric acid; the hydroxy or mercapto group in dialuric and thiodialuric acids is substituted to form 5-substituted derivatives of these acids.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 267–269, February, 1973.     

Reactions of hydrazine derivatives

Conditions were worked out for the synthesis of a number of 1-arylpyrazolidines with alkyl groups in the 4 and 5 positions of the five-membered ring by reduction of the corresponding 3- or 5-pyrazolidones with lithium aluminum hydride.See [1, 2] for communications XLVI And XLVII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 118–121, January, 1971.     

Reactions of hydrazine derivatives

On the basis of a combined study of chemical properties and UV, IR, PMR, and mass spectra, it has been shown that the product of the transformation of 3,4-tetramethylene-5, 5-pentamethylenepyrazoline under the action of sulfur has the structure of 3-pentyl-4,5,6,7-tetrahydroindazole.For part XLIV, see [1].